This invention relates to antenna tuning circuits and, more particularly, to an automatic antenna tuning circuit for indoor use with convnetional FM and television receivers.
Over the years, a wide variety of antennas have been developed for use with conventional FM and television receivers. These antenna designs range from large outdoor multi-element dipole antennas to small folded dipole and loop-type indoor antennas. One problem with prior art indoor antennas is that, as a result of their small size, they possess a very high Q, and consequently a very narrow bandwidth. Typically, these antennas are sized for optimum performance in the center of the receiver bandwidth. As a result of their narrowband characteristics, these antennas provide poor performance on either side of that center frequency. Some indoor antennas have elements which are manually adjustable in size, but such adjustments are difficult to accomplish with any degree of accuracy, and must be changed for each change in receiver frequency.
Accordingly, it is an object of the present invention to provide a new antenna tuning system which improves the performance of small antennas.
It is another object of the present invention to provide an antenna tuning system which can be used with conventional FM and television receivers without any modifications thereto, and which is completely automatic in its operation.